Characteristics of a deep crack occurred on intact molars without restoration

Abstract

The objective of this study was to investigate the characteristics of a deep crack in intact teeth with no restoration. The molars which were treated endodontically in the Department of Conservative Dentistry at Wonkwang University Daejeon Dental Hospital were screened and evaluated from January 2017 to June 2018. Clinical records of endodontically treated molars were reviewed and the molars diagnosed as cracked tooth were selected. From clinical records, only the cases where the crack line was confirmed to extend to the wall of access cavity were included in the study. Teeth with dental caries, restorations, or fractures at the time of diagnosis were excluded. General and pretreatment data of 85 cracked teeth were collected from the clinical records. The relatively deep cracks from intact molars occurred two times more in the maxillary molars than in the mandibular molars, and five times more in males than in females. Crack lines observed from access cavity wall were significantly different in maxillary and mandibular molars. The contralateral symmetrical molars of the cracked tooth had ‘crack or fracture’ or was ‘extracted’ at a higher rate than the occluding teeth. Deep cracks in intact molar had different characteristics from general cracks. In case someone has a cracked tooth, it may be important to check the condition of the contralateral tooth and consider the intervention.